1. Field of the Invention
The present invention pertains to the manufacture of flexible packages, such as plastic bags, and in particular to packages having fastener closures employing sliders.
2. Description of the Related Art
With the recent emphasis in providing consumers with bulk quantities of various commodities, such as food products, reclosable packages have become increasingly popular. One of the most popular means of providing reclosability is to employ zippers of various types, particularly zippers which are compatible with flexible packages of plastic film construction. Manufacturers of food products and other commodities are concerned with filling the contents of a flexible package as quickly and economically as possible. It is important that the opening provided by the fastener be made as large as practically possible. Consumers or other end users also prefer large sized openings for easy extraction of products from the package interior. Even with large openings, however, products within the package may interfere with fastener operation when product poured or otherwise dispensed from the package becomes entrained in the fastener components.
Other improvements to flexible reclosable packages are being sought. For example, when handling products comprised of numerous small pieces, such as shredded cheese or cereal, for example, it is generally desirable to have the package formed into a pouch which is open at one end, or along one side, so as to allow product to be poured or shaken through the reclosable opening. It is desirable that the product be allowed to freely flow past the reclosable opening. Preferably, the path taken by the product within the package should be made as smooth as possible.
Although improvements have been made in the art of plastic welding and joining, manufacturers of consumer products employing high speed production techniques are continually seeking improved package forming methods and equipment.
It is an object of the invention to provide apparatus for manufacturing improved, shrouded and unshrouded flexible packages.
Another object of the invention is to provide apparatus for making reclosable packages having fastener sliders which are protected as the package contents are poured out or otherwise extracted.
A further object of the invention is to provide apparatus for making a reclosable plastic package having a slider fastener with improved containment of the slider in a manner which also optimizes the size of the bag opening.
A further object of the invention is to provide apparatus for making a plastic bag having a slider fastener with an improved end xe2x80x9ccrushxe2x80x9d stop of the fastener tracks.
These and other objects of the invention are provided in a horizontal form-fill seal machine for combined in-line and rotational manufacturing of food packages that have a shrouded mated fastener tracks with slider closures, that comprise a supply of web material which extends in an in-line machine direction and defines a serial succession of package sidewalls and extends in the machine direction. A supply of mated fastener tracks, that includes a first track with a shorter flange mated to a second track with a longer flange. A fold member that receives the web material. A web drive that transports web material over fold member in the in-line machine direction, and folds web material into overlying side-by-side portions, one against the other, to form a continuous succession of folded package portions that extends in the machine direction and has pairs of overlying first and second package sidewalls that have overlying free edges with shroud portions at the free edges. A slider member mateable with mated fastener tracks for movement along mated fastener tracks in opposite directions to open and close mated fastener tracks. A slider installation member inserting slider member onto mated fastener tracks. Fastener seal bars extending in the machine direction, sealing a portion of each flange of fastener tracks to first sidewall, leaving the flanges free to attach to the second package sidewall. Side seal bars extending at an angle to machine direction, sealing portions of a package sidewall together to form respective side seals of the food package. A filler member filling product into a package. A sidewall sealing member sealing second package sidewall to second track flange. A shroud seal member that seals the free edges of the package sidewalls to form a shroud that encloses the fastener tracks, to form a completed food package. A turntable member mounted filler member, side wall seal member and shroud seal member for movement in a rotational direction, and a transfer station mounted on the turntable for transferring completed food package away from the machine.